This invention relates to support assemblies and is more particularly concerned with removable supports for luggage and the like.
The application of casters to luggage, especially to larger suitcases, enjoys wide popularity. The ability to move heavily loaded suitcases on wheels is highly advantageous to travelers. However, there are times when wheels are unnecessary and when easy removal of luggage casters is desirable. It is also desirable to be able to employ removable casters and stationary runners on luggage interchangeably.
There have been many prior proposals for the provision of detachable supports, such as casters, for luggage. For example, U.S. Pat. No. 4,026,570, assigned to the same assignee as the present invention, discloses a wheel unit with lugs that are inserted into slots of a base plate, the wheel unit being retained upon the base plate by a spring engaging one of the lugs. In the support of U.S. Pat. No. 3,947,917 a runner for luggage provides a stud to which a caster may be attached by means of a spring clip or slidable bolt member. U.S. Pat. No. 3,935,613 discloses a support assembly for luggage in which a base plate has a resilient member that becomes latched to a detachable roller unit. Similarly, in U.S. Pat. No. 3,987,875 a base plate has integrally molded projections that latch onto a detachable roller unit. Casters with resilient latches for holding the casters in receptacles are disclosed by U.S. Pat. Nos. 1,541,280 and 2,478,563. The caster of U.S. Pat. No. 2,800,679 has flanges that enter channels of a mounting plate and that are retained therein merely by friction.
The goals to be achieved in the provision of a satisfactory removable luggage caster are, to some extent, at cross purposes. On the one hand, the entire caster assembly should be economical to manufacture, and the removable caster portion should be easy to attach to luggage and easy to remove. On the other hand, the caster assembly should be strong enough to withstand heavy loads and high impact forces, and the removable caster portion should not become detached unintentionally. Prior removable luggage casters fail to achieve all of these goals. Furthermore, in the prior art a base plate that is permanently attached to the luggage commonly includes a mechanism with moving parts to engage and hold the removable caster unit. If the mechanism fails, it is necessary to replace the base plate, and this may involve removing rivets from the base plate and the luggage.